In a mixing bowl, cream together the softened butter, brown sugar, granulated sugar, and vanilla extract until smooth and creamy.
Gradually add the flour and salt to the butter-sugar mixture, mixing until well combined. If the dough seems too dry, add milk, one tablespoon at a time, until you reach your desired consistency.
Fold in the chocolate chips, if using, until evenly distributed throughout the dough.
Once the cookie dough is mixed, it's ready to eat! Enjoy it by the spoonful or use it as a topping for ice cream, brownies, or cupcakes.
Store any leftovers in an airtight container in the refrigerator for up to one week.